2015 toyota sienna trac off check engine light on

I have a 2015 Toyota Sienna with 16,000 miles. I use it as a camper mainly for trips. Got into a tight spot and had to do a turnaround and my cargo luggage attachment on the back bumper rubbed a tree and hung the van up a little before I pressed on the gas. Took a small piece of the bark off the tree. Immediately after the trac off and engine light came on. I’ve checked the gas cap, reset the cg and ts terminals, disconnected the battery for five minutes, pushed the trac button for several minutes after starting up the van. Nothing has worked. I can’t imagine this would have damaged the engine, it wasn’t that big of a deal. Any ideas on what might be able to solve my problem? I haven’t tried an OBD2 but from reading other similar problems probably would get false readings. Thanks for any ideas, I really can’t afford a big repair job.

If the Check Engine light turns on, the Trac off light will turn on automatically.

This is because the traction control will not function if there’s a problem with the engine that causes the Check Engine light to come on.

So, find out why the Check Engine light is on, remedy that problem and the Trac off light will turn off.



From what I’ve read the trac off and check engine light come on together. I’ve read if you skid or even go thru a large puddle these lights can come on together. The trac control sensors on each wheel can give a false reading to the engine after a medium skid, rough terrain event, etc. I feel pretty certain it is not an engine problem.

Doesn’t matter how you feel about it. Only data matters. Get the codes read as a first step to fixing it. Anything else is just a guess. Post the actual codes here and we will try and help.


It will take me a day or so to be able to get the codes. Something I left out, once I disconnected the battery for 5 minutes and then reset the ts and cg terminals, restarted the van the check engine trac off lights went off. After driving a few minutes they came back on. I shut off the van and hold down the trac button and restart and the lights are off. After a short time the lights come back on. Read other posts where they have gotten ECM codes for replacement of the canister or replace engine. Hope that won’t be the case.

Seems unlikely you’ll find a “replace engine” code stored in the computer’s memory :wink: You could try resetting the computers again, this time disconnect the battery overnight. 5 minutes may not be long enough. It appears the computer thinks there’s a problem and has stored this info in its memory and doesn’t want you to forget it. That’s why the warning lights keep turning back on. It may be necessary, after you satisfy the computer nothing is wrong, to use a scan tool to turn them off. I doubt the tree incident did much in the way of permanent damage to the drivetrain.

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I had these warnings from a failing battery. Try charging the battery.


Finally was able to do the scan, got one code P0306, cylinder 6 misfire detected. Took my new battery out of my RAV and put in the Sienna prior to the scan.

There’s a long warranty on the emissions systems, and you should do a bit of research.

Here’s an official summary, from Toyota, for a 2015 Camry.


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If the battery replacement doesn’t solve the misfire code — may take some drive cycles for it to disappear — they way to diagnose misfires is to swap stuff between cylinders. For example if you swapped the spark plugs between cylinder 6 and 5, and the misfire moved from 6 to 5, excellent chance the problem is a faulty spark plug. Coils, injectors, wiring, etc are all possibilities for swapping. Misfires can also be caused by low cylinder compression.

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I’ve got the new battery unhooked overnight, tomorrow I’ll reset terminals ts and cg and see if that makes a difference. I may need to beef up the gas, it has been sitting in there for a few months now. If that doesn’t help, I’ll start swapping what you suggested. If that doesn’t help, I’ll have to bite the bulet and take it into the shop.

Reconnected the battery and reset the ts and cg terminals. Added some gas treatment. The engine light came back on after a few minutes. Did the ODR2 scan again and removed the pending codes (got rid of the check engine light) but got a new code P03056, engine coil f primary control circuit open. I’m driving the van hoping the codes will eventually go away. The van sounds good, idle is at the correct speed so hope this will eventually stop tripping…

Fault P0356; Ignition coil “F” Primary/Secondary circuit usually indicates a failed ignition coil. Unusual for a failure at such low miles, I have replaced many of them on vehicles with the 2GR engine with 80,000 or more miles.

That coil is easy to replace, front bank, last cylinder.

Changed out the spark plug on number 6 after swapping ignition coils with no change. Changing the spark plug seems to have fixed the problem. Took it for a drive and no check engine light or trac off came up. Will be putting hi octane gas in it tomorrow and next several fill ups. Really happy if this is all it needed. Thank you to everyone for your comments and advice, it really helped.

Why are putting high octane gas in a vehicle that doesn’t require it?


I’m thinking the gas that is in there is old and fouling the plugs. The hi test would perk up the bad gas and run it through cleaner?

High octane gas just has a higher octane content than regular gas.Which means it’s harder to ignite.

Both regular and premium gas contain the same amount of detergents.

Don’t waste your money.


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Thank you, I had no idea. I’ll put the 89 octane in it. I appreciate the tip and you saving me some money!

You should only need 87 , your manual will confirm that.

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Did a little research, looks like I can fill up at EXXON, Shell or BP with 87 octane and still get the quality detergent I need. Thank you!